Formulations containing cynara scolymus and phaseolus vulgaris extracts which are useful in the treatment of obesity

ABSTRACT

The present invention relates to a  Cynara scolymus  extract with a high content of caffeoylquinic acids, and a composition containing said  Cynara scolymus  extract with a  Phaseolus vulgaris  extract. 
     Said composition is useful in reducing obesity as it reduces cholesterol, triglycerides and blood glucose by sensitising the cells to insulin. This combination, when taken before meals, reduces the appetite, leading to a reduction in body weight. The extracts are preferably formulated in  Oenothera biennis  oil, fish oil, or oils rich in unsaturated ω-3 fatty acids.

FIELD OF INVENTION

The present invention relates to formulations containing an extract ofCynara scolymus, preferably with a high content of caffeoylquinic acids,and an extract of Phaseolus vulgaris, in a ratio between 1:0.25 and 1:1.

This composition is useful in reducing obesity because it reducescholesterol, triglycerides, blood glucose and the appetite.

BACKGROUND OF THE INVENTION

Obesity is currently one of the major health problems, especially in theindustrialized countries, with serious consequences in cardiocirculatoryand skeletal terms.

Carbohydrates are an important source of calories, and contribute to thesynthesis of fats in individuals predisposed to obesity or type IIdiabetes. As hyperglycaemia leads to an increase in energy deposits, theavailability of substances that reduce bioavailable glucose is veryimportant. As starches are the main source of glucose, specificα-glucosidase and α-amylase inhibitors, obtained from plant materials orby synthesis, have been studied. It has long been known that some seedsand pulses contain substances which can have adverse effects on the dietif eaten before they are completely cooked. Many pulses contain proteaseinhibitors, amylase inhibitors and substances that discourage predatorsfrom continuing to use them by reducing the appetite. These substances,called phytohaemagglutinins, can cause hyperplasia of the pancreas athigh doses, but can be useful in appetite control at lower doses.

At high doses, these lectins survive the intestinal transit and bond tothe enterocytes where they cause the secretion of cholecystokinin, atrophic hormone that stimulates secretion by the pancreas, consequentlycausing its enlargement. Cholecystokinin also has favourable effects,because it reduces the appetite by reducing gastric motility.

It is known from the literature that aqueous or hydroalcoholic extractsof Cynara scolymus have hypocholesterolaemic, choleretic andantidyspeptic activity. The hypocholesterolaemic activity, which hasbeen reported for many years, is associated with two classes ofsubstances: cynarin, a dicaffeoylquinic acid, and flavonoids derivingfrom luteolin, which have been demonstrated in vitro to inhibitcholesterol synthesis in the liver. Part of the activity is associatedwith the choleretic action specific to Cynara scolymus extracts. Aprocess of extraction of Cynara scolymus is described in WO 2007/006391.

DESCRIPTION OF THE INVENTION

It has now been found that by combining Cynara scolymus extracts withPhaseolus vulgaris extracts, surprising effects on the reduction of bodyweight are obtained, proportional to the dose administered; the data inrats suggested that the effect on body weight reduction is not simplyassociated with a reduction in the blood glucose level, but also with adefinite reduction in food consumption. Various pharmacologicalexperiments demonstrate that this reduced food intake, despiteunrestricted access to food, is associated not with a simply toxiceffect, but with a modification in the desire to eat.

The combination of an artichoke extract, which helps to increase theelimination of fats and glucose by modifying glucose transport in theintestine and liver, with substances that reduce the metabolism ofstarch, is particularly important in the maintenance of body weight, andblocks its progress.

DETAILED DESCRIPTION OF THE INVENTION

The extracts which can be used according to this invention arecommercial artichoke extracts, extracts according to WO 2007/006391, oran artichoke extract with a high content of caffeoylquinic acids andluteolin glycosides, obtainable by extraction from undried edible headswith C1-C3 alcohols or mixtures thereof with water.

The extraction from the undried edible heads of Cynara scolymus ispreferably performed with ethanol or ethanol/water mixtures, especiallyethanol/water in the ratio of 7:3 v/v. After purification, an extract isobtained which differs from known extracts due to its high content ofcaffeoylquinic acids and flavonoids expressed as luteolin glycosides.The extract also possesses hypoglycaemic activity. The extract can beprepared from various globe artichoke cultivars, preferably from thespiny variety, and even more preferably from the Sardinian spinyvariety.

The preferred artichoke extract has a caffeoylquinic acid contentranging between 30 and 60%, preferably around 45%, and a flavonoidcontent, expressed as luteolin glycosides, ranging between 2 and 5%,preferably around 2.5%.

A commercial extract can be used as Phaseolus vulgaris extract; however,the Phaseolus vulgaris extract described in PCT/EP2006/012012 ispreferred. Said extract is obtainable by extraction from Phaseolus sp.with mixtures of ethanol and water, and is characterised by analpha-amylase inhibitor content of between 1200 and 1600 USP/mg (HPLCtitre between 7 and 14% w/w) and a phytohaemagglutinin content ofbetween 12,000 and 30,000 HAU/g. Said extract can be obtained by aprocess which comprises:

-   -   a) extraction of Phaseolus sp. with aqueous buffers having a pH        ranging between 3 and 6.5 and subsequent separation of the        extract from the biomass, which can possibly be further        extracted with the buffer until exhaustion in alpha-amylase and        phytohaemagglutinin inhibitors;    -   b) filtration or centrifugation of the combined extracts and        concentration to a volume corresponding to approx. 10% of the        weight of the biomass of the starting extract after        centrifugation;    -   c) differential precipitation of the concentrated aqueous        extract with diluted ethanol, to a final concentration between        60 and 70% v/v;    -   d) separation of precipitate and reprecipitation from        demineralised water with 60% ethanol or diafiltration on a        membrane with a 10,000 Da cut-off, and drying of precipitation        residue.

The combination of the two extracts in a ratio between 1:0.25 and 1:1comprises doses ranging from 50 to 500 mg per dose for the Cynarascolymus extract, preferably 200 mg, and from 50 to 200 mg per dose forthe Phaseolus vulgaris extract, preferably 100 mg, to be taken beforemeals or whenever foods rich in carbohydrates are eaten.

The hypoglycaemic activity of the composition according to the inventionis surprisingly superior to the hypoglycaemic activity of the twoconstituents alone. The results, obtained according to the methoddescribed by Tormo M A et al., Br. J. Nutr. 96, 539, 2006, are set outin the Table. Table—Effect of purified Artichoke extract, Phaseolusvulgaris extract and their combination on glycemia in Wistar rats givena restricted amount of food with a 1 hour/day limited access.

TABLE Effect of purified Artichoke extract, Phaseolus vulgaris extractand their combination on glycemia in Wister rats given a restrictedamount of food with a 1 hour/day limited access. Purified artichokePhaseolus vulgaris AUC of plasma extract mg/kg p.o. extract mg/kg p.o.glucose levels (mg/dL) 0 0 30800 ± 950 50 0 25100 ± 700* (−18%) 0 5027700 ± 600 (−10%) 25 25 19800 ± 800** (−36%) Number of animals/group: 8*p < 0.05 **p < 0.01 vs controls

The composition according to the invention is suitable to beincorporated in pharmaceutical formulations such as tablets, dragées,soft and hard gelatin capsules and cellulose capsules. The extracts arepreferably formulated in oils rich in polyunsaturated ω3/ω6 acids suchas Oenothera biennis (evening primrose) oil.

The same results as observed in laboratory animals have been confirmedin humans at doses of between 50 and 1000 mg a day.

The following examples illustrate the invention in detail.

EXAMPLE 1 Preparation of Extract of Cynara scolymus vr. Spinosus

Load 2 kg of Cynara scolymus heads, vr. Sardinian spinosus, chopped andfrozen at the time of harvesting, into a percolator with a heatingjacket, and cover with 4760 ml of 95° EtOH to obtain an alcohol contentof approx. 70% (assuming an 85% water content in the plant). Maintain incontact for 3 hours at 70° C., then unload. In the successiveextractions, extract with EtOH 70% v/v at 70° C., covering the plant,with a minimum contact time of 3 hours. Perform a total of 5extractions, using approx. 15 l of solvent.

Combine the percolates and concentrate under vacuum at 35° C. to approx.15% of dried residue.

Leave to cool at ambient temperature, separate the insoluble fraction,and load the clear aqueous solution into a column packed with 530 ml ofXAD-7 HP resin.

Wash the column, first with 530 ml of water (eliminating the eluate) andthen with 1325 ml of 90% EtOH. Concentrate the hydroethanolic eluate anddry at 50° C. under vacuum for 24 hours. 18.59 g of purified extractwill be obtained. HPLC titres: caffeoylquinic acids 49.13%, flavonoids2.68%.

EXAMPLE 2 Formulation of Cynara scolymus and Phaseolus vulgaris ExtractsInto Oily Suspension for Soft Gelatin Capsules

Unit composition:

Cynara scolymus extract 100 mg Phaseolus vulgaris extract 100 mgGlyceryl monostearate  30 mg Soya lecithin  10 mg Oenothera biennis oilq.s. for 700 mg

Manufacturing Process

-   -   Heat Oenothera biennis oil to approx. 70° C. and melt the        glyceryl monostearate in it under agitation.    -   Add the soya lecithin to the solution obtained.    -   Disperse the Cynara scolymus and Phaseolus vulgaris extracts in        the solution obtained, ensuring even distribution.    -   Gradually cool the solution obtained, keeping it under        agitation.

EXAMPLE 3 Formulation of Cynara scolymus and Phaseolus vulgaris ExtractsInto Hard Gelatin Capsules

Unit composition:

Cynara scolymus extract 150 mg Phaseolus vulgaris extract  50 mgMicrocrystalline cellulose 200 mg Lactose  95 mg Silicon dioxide  5 mg

Manufacturing Process

-   -   Mix extracts, microcrystalline cellulose, lactose and silicon        dioxide.    -   Divide the mixture obtained between hard gelatin capsules.

EXAMPLE 4 Formulation of Cynara scolymus and Phaseolus vulgaris ExtractsInto Modified-Release Granules

Unit composition:

Cynara scolymus extract 100 mg  Phaseolus vulgaris extract 50 mgMicrocrystalline cellulose 100 mg  Povidone 10 mg Sodiumcarboxymethylcellulose  8 mg Methacrylic acid copolymer 50 mg Triethylcitrate 3.2 mg  Talc  8 mg Simeticone 0.3 mg 

Manufacturing Process

-   -   Granulate the extracts, microcrystalline cellulose and sodium        carboxymethylcellulose with an aqueous solution of povidone.    -   Dry and calibrate the granulate obtained.    -   Coat granules with an aqueous suspension of methacrylic acid        copolymer, triethyl citrate, talc and simeticone.

EXAMPLE 5 Formulation of Cynara scolymus and Phaseolus vulgaris ExtractsInto Immediate-Release Granules

Unit Composition:

Cynara scolymus extract 100 mg  Phaseolus vulgaris extract 50 mgMicrocrystalline cellulose 100 mg  Povidone 10 mg Sodiumcarboxymethylcellulose  8 mg

Manufacturing Process

-   -   Granulate the extracts, microcrystalline cellulose and sodium        carboxymethylcellulose with an aqueous solution of povidone.    -   Dry and calibrate the granulate obtained.

EXAMPLE 6 Mixture of Cynara scolymus and Phaseolus vulgaris ExtractGranulates With Different Release Profiles

Manufacturing Process

-   -   Mix 50% of the granulate described in example 4 with 50% of the        granulate described in example 5.

Divide the mixture obtained between hard gelatin capsules.

1. A composition comprising an extract of Cynara scolymus and an extractof Phaseolus vulgaris in a ratio between 1:0.25 and 1:1.
 2. Acomposition as claimed in claim 1, wherein the Cynara scolymus extracthas a caffeoylquinic acid content ranging between 30 and 60% and aluteolin glycoside content ranging between 2 and 5%.
 3. A composition asclaimed in claim 1, wherein the Phaseolus vulgaris extract ischaracterised by an alpha-amylase inhibitor content of between 1200 and1600 USP/mg (HPLC titre between 7 and 14% w/w) and a phytohaemagglutinincontent ranging between 12,000 and 30,000 HAU/g.
 4. A composition asclaimed in claim 1, further containing Oenothera biennis oil. 5.(canceled)
 6. A composition as claimed in claim 2, wherein the Phaseolusvulgaris extract is characterised by an alpha-amylase inhibitor contentof between 1200 and 1600 USP/mg (HPLC titre between 7 and 14% w/w) and aphytohaemagglutinin content ranging between 12,000 and 30,000 HAU/g. 7.A composition as claimed in claim 2, further containing Oenotherabiennis oil.
 8. A composition as claimed in claim 3, further containingOenothera biennis oil.
 9. A composition as claimed in claim 6, furthercontaining Oenothera biennis oil.